1. Field of the Invention
The present invention relates to a disc player for recording information into and/or reproducing recorded information from a disc such as a compact disc (CD), a CD-ROM, a digital video disc (DVD), and a DVD-ROM. More particularly, the present invention relates to a disc roller position-changing apparatus for bringing a disc roller for transferring a disc into contact with, or separating it from, a disc in a tray-less disc player such as a car disc player, and a disc player having such a disc roller position-changing apparatus.
2. Description of the Related Art
In general, a car disc player has a tray-less disc loading system loading a disc to a position for recording information into or reproducing information from a disc without a disc tray due to spatial restriction. When a disc is entered into the disc player from the front direction, a disc loading system loads the disc to a chucking position on a turntable using a disc roller and then seats the disc on the turntable to rotate thereon. The disc roller is lowered and separated from the disc by a disc roller position-changing apparatus so as not to interfere with the rotation of the disc. When the disc has been seated on the turntable, the disc player may record information into or reproduce recorded information from the disc as an optical pickup moves in the radial direction of the disc while the disc is rotating on the turntable.
FIGS. 1 to 3 show a conventional car disc player.
The disc player has a disc roller position-changing apparatus 12 for lifting or lowering a disc roller 11 to come in contact with, or separate from, a first disc 1 having a size of 120 mm or a second disc 2 having a size of 80 mm.
The disc roller position-changing apparatus 12 includes a roller bracket 13, a projection pin 15 and a guide slot 34.
Both front opposite ends of the roller bracket 13 are respectively formed with first and second hinge axles 18, 18′ which are supported by first and second support brackets 19, 19′ provided in the main chassis 10, and both rear opposite ends of the roller bracket 13 are respectively formed with first and second support bosses 21, 21′ for supporting opposite ends of an axle 11a of the disc roller 11.
The front edge of the roller bracket 13 is formed with disc takeout prevention plates 17. The disc takeout prevention plates 17 block a disc transfer passage behind the first or second disc 1 or 2 after the first or second disc has been loaded, thereby preventing the disc from being forcibly taken out of the disc player.
The projection pin 15 is formed adjacent to the first support boss 21 of the roller bracket 13 to be projected toward a slider 30.
The guide slot 34 is formed in the slider 30 opposite to the projection pin 15 so that the guide slot 34 receives the projection pin 15, and the guide slot 34 guides the projection pin 15 to be lifted or lowered as the slider 30 moves.
Now, the disc loading operation of the disc player configured as described above is described.
As shown in FIG. 1, when a disc, e.g., a first disc 1 having a size of 120 mm is entered into a housing 50 in the loading direction, i.e., in the A1 direction, a controller (not shown) drives a driving motor 20 (see FIG. 3) on the basis of a signal from a disc detection sensor (not shown) for detecting the entry of the first disc 1. As a result, the first disc 1 is drawn into the housing 50 by the disc roller 11, wherein the disc roller 11 receives power from the driving motor 20 through a plurality of connection gears 22, 23, 24, 25, 26.
Thereafter, when the first disc 1 pushes first and second guide rollers 43, 44 of first and second pivot plates 41, 42, the first and second pivot plates 41, 42 pivot in the C and D directions, respectively. Consequently, a contact part 47 of the second pivot plate 42 pushes one end 49 of a first pushing lever 48. Then, while the first pushing lever 48 is rotating in the C direction, the other end 51 of the first pushing lever 48 pushes the slider 30 by a predetermined distance in the A2 direction.
A rack gear 31 is connected to a driving gear 32 which receives power of the of the driving motor 20 through the plurality of connection gears 22, 23, 36, 37 as shown in FIG. 3, with the result that the power of the driving gear 32 is transmitted to the rack gear 31 and thus the slider 30 is continuously moved in the A2 direction.
As the slider 30 moves, as shown in FIGS. 4 and 5, the cam slit 61 of the sub chassis 60 is guided by the movement of the cam lug 33 of the slider 30 and the sub chassis 60 is moved in the B1 direction from a position shown in FIGS. 1 and 2.
When the sub chassis 60 moves in the B1 direction as mentioned above, the guide slot 68 in the second vertical surface 67 of the sub chassis 60 also moves in the B1 direction. As a result, the projection pin 83 formed on the first vertical surface 82 of the chuck bracket 81 of the disc chucking apparatus 80 is guided and lowered by the guide slot 68, as shown in FIG. 5. As the projection pin 83 is lowered, the chuck bracket 81 pivots counterclockwise about the hinge axle 86 thereby being lowered, with the result that a clamper 90 installed at the front end of the chuck bracket 81 rotatably clamps the first disc 1 on the turntable 95.
In addition, as the slider 30 moves in the A2 direction, the projection pin 15 formed on the roller bracket 13 is guided and lowered by the guide slot 34 provided in the slider 30. As a result, the roller bracket 13 is rotated clockwise about the first and second hinge axles 18, 18′, and the disc roller 11 supported by the roller bracket 13 is lowered and spaced from the first disc. At this time, the disc takeout prevention plates 17 formed at the front edge of the roller bracket 13 are vertically positioned to block the disc transferring passage behind the disc 1, so that the disc cannot be taken out from the disc player.
From this state, the first disc 1 is rotated on the turntable 95 and an optical pickup (not shown) records information into or reproduces recorded information from the first disc 1.
After information has been recorded or reproduced, the first disc 1 is unloaded as follows.
First, the driving motor 20 is reversely rotated to return the slider 30 in the A1 direction. Next, the sub chassis 60 is returned to its original position in the B2 direction (FIG. 1). As a result, the disc chucking apparatus 80 and the disc roller position-changing apparatus 12 are operated in the reversed sequence as to the first disc loading operation, and the first disc 1 is separated from the turntable 95 and at the same time comes into contact with the disc roller 11, whereby the first disc 1 is discharged out of the housing 50 by the disc roller 11.
However, the conventional car disc player configured as described above has a problem in that the roller bracket 13 should be rotated over a relatively large angle so as to bring the disc roller 11 into a contact with, or separate it from the first or second disc 1 or 2, and at the same time, to position the disc takeout prevention plate 17 at a vertical position blocking the disc transferring passage or at an open position opening the disc transferring passage, because the roller bracket 11 of the disc roller position-changing apparatus 12 has a construction fixedly supported by the first and second hinge axles 18, 18′, whereby it is necessary to design the operating space required for rotating the roller bracket 13 and the height h of the guide slot 34 for rotating the roller bracket 13 over a predetermined range of arc to have large sizes, respectively.
If the operating space of the roller bracket 13 and the height of the guide slot 34 are designed to have large sizes, respectively, the entire thickness of a resultant disc player will increase and the graceful appearance of the disc player will be diminished.